Hint: Envelopes:Batman can find hidden envelopes throughout the game.
The first one is on the Rooftop Battle level, the second is on
the Bridge level, the third is on the Plant Electrocution 2 level,
the fourth is on the Gasworks Level, and the fifth is on the SWAT
Chase level. If find one, it will have a letter on it. They unlock
infinite weapons, infinite charge bar, infinite health, double
damage, and invisibility. They are awarded by the order found,
and not the letter. For example, if you collect Envelope E furstm
you will get infinite weapons instead of invisibility.Sanjay Bappudi.

Hint: Bridge: Envelope B:Knock out the thug at the start of the level. You should
see the glowing item on the left when you start. Climb the ladder
and jump/glide around the crate onto the other crate. Then, glide
onto the platform with the letter.

Hint: Gasworks: Envelope E:You will reach a room with two levels, each floor with
two goons on them. First, take out the goons. Then, look around
on the lower floor until you see a sewer pipe with boxes in the
sewage. Carefully glide down and land on the first box. Jump over
the next few boxes and pick up the envelope with an "E"
on it. Finish the game and the "Infinite Health" cheat
will be unlocked.

Hint: Plant Electrocution 2: Envelope C:
You will start the Plant Electrocution 2 level by sliding
down towards some holes in the ground. The second hole is not
fatal. Fall into it and glide (to avoid minor damage). You will
see a lit area. Glide down there and pick up the item you find
inside. Use the grapnel to exit, jump out of the hole, and finish
the slide. The item you picked up should be the key do the door
right beside the vines behind the glass. Go inside and fight one
of the "Plant Men". You will find an envelope that has
a "C" on it in the room. When you finish the game, you
can activate this cheat for all weapons and unlimited ammunition.
Joker.

Hint: Rooftop Battle: Envelope A:When the clowns chase Mary, you will go up to the rooftops.
Grapple hook up to her roof and beat up the white clown. Go up
to the next roof, where you are on a little balcony. Jump across,
then go in to see a thug run across a hall with the girl. Follow
and he will jump off the roof. Follow, look down, and drop to
lowest edge. Walk along to left until at the corner the grapple
icon appears Grapple over, go in the door and pick up Envelope
A.

Hint: SWAT Chase: Envelope D:You will enter the elevator shaft. Ride the elevator
all the way down until it stops. Get off the elevator and wait
for it to rise again. After it rises, jump down to the bottom
and use first person mode to find the control box. Use a Batarang
to disable it and the door behind it will open. Stay clear of
the elevator and wait for the correct time to get in the open
room. Inside the room is "Secret Key 2." Get out of
the room and ride the elevator up to the top. At the top there
is a door that is supposed to be locked. The key opens the door,
and inside is an envelope with the letter "D" on it.
Finish the game and the "Infinite Special Move Bar"
cheat will be unlocked.

Hint: Flash bombs:Press Action + Guard to use flash bombs.
They cannot be selected in the gadget/first person view.

Hint: Smoke bombs:In the level after the Batcave training, when you get
to the area with a Joker thug, look around the big square. You
will eventually find a ladder. Climb up the ladder, then look
around for a box. Pick it up to get smoke bombs.speyton.

Hint: Hacking into Issac Evers files:Find the second wire of the color you need (that is
not powered). You need to make the powered wire reach the non-powered
one. For example, if you work on blue, you need to connect the
live blue wire to the dead one.

Hint: Blimp puzzle:Look in your inventory and examine the disc Batman
picked up before fighting Mr. Freeze. It will reveal possible
colors that work with the Blimp puzzle. The combination is Purple
and Green. Make the color purple, "mix tubes", then
make the color green.

Hint: FunnyBones Warehouse lock:Instead of trying the 999 possibilities on the lock,
look for figurines like the one in the room near your starting
location. There is another one behind trucks and one outside the
fence when you get on the roof of the building with the first
figurine. The combination is 619 (from left to right).

Hint: Defeating Mr. Freeze:Do not charge at him or you will be thrown and probably
get frozen. Enter first-person mode and equip your demolition
charges. Make sure Mr. Freeze is following you. Look up to find
glass tanks moving on a hook. When he is under one, fire at it
with your charges then detonate it so that it lands on him. Repeat
this until you get a move where Batman grabs Mr. Freeze's gun
and freezes him to stop him from burning.